diff --git a/experiments/cf_asexual_evo.py b/experiments/cf_asexual_evo.py
index 091336de..f913d8dd 100644
--- a/experiments/cf_asexual_evo.py
+++ b/experiments/cf_asexual_evo.py
@@ -33,11 +33,13 @@
     SavedProfile,
 )
 from emevo.reward_fn import (
+    ExponentialReward,
     LinearReward,
     RewardFn,
     SigmoidReward,
     SigmoidReward_01,
     mutate_reward_fn,
+    serialize_weight,
 )
 from emevo.rl.ppo_normal import (
     NormalPPONet,
@@ -54,6 +56,7 @@
 
 class RewardKind(str, enum.Enum):
     LINEAR = "linear"
+    EXPONENTIAL = "exponential"
     SIGMOID = "sigmoid"
     SIGMOID_01 = "sigmoid-01"
 
@@ -94,30 +97,22 @@ def extract_sigmoid(
         return jnp.concatenate((collision, act_input), axis=1), energy
 
 
-def slice_last(w: jax.Array, i: int) -> jax.Array:
-    return jnp.squeeze(jax.lax.slice_in_dim(w, i, i + 1, axis=-1))
-
-
-def linear_reward_serializer(w: jax.Array) -> dict[str, jax.Array]:
-    return {
-        "agent": slice_last(w, 0),
-        "food": slice_last(w, 1),
-        "wall": slice_last(w, 2),
-        "action": slice_last(w, 3),
-    }
+def exp_reward_serializer(w: jax.Array, scale: jax.Array) -> dict[str, jax.Array]:
+    w_dict = serialize_weight(w, ["w_agent", "w_food", "w_wall", "w_action"])
+    scale_dict = serialize_weight(
+        scale,
+        ["scale_agent", "scale_food", "scale_wall", "scale_action"],
+    )
+    return w_dict | scale_dict
 
 
 def sigmoid_reward_serializer(w: jax.Array, alpha: jax.Array) -> dict[str, jax.Array]:
-    return {
-        "w_agent": slice_last(w, 0),
-        "w_food": slice_last(w, 1),
-        "w_wall": slice_last(w, 2),
-        "w_action": slice_last(w, 3),
-        "alpha_agent": slice_last(alpha, 0),
-        "alpha_food": slice_last(alpha, 1),
-        "alpha_wall": slice_last(alpha, 2),
-        "alpha_action": slice_last(alpha, 3),
-    }
+    w_dict = serialize_weight(w, ["w_agent", "w_food", "w_wall", "w_action"])
+    alpha_dict = serialize_weight(
+        alpha,
+        ["alpha_agent", "alpha_food", "alpha_wall", "alpha_action"],
+    )
+    return w_dict | alpha_dict
 
 
 def exec_rollout(
@@ -459,7 +454,16 @@ def evolve(
         reward_fn_instance = LinearReward(
             **common_rewardfn_args,
             extractor=reward_extracor.extract_linear,
-            serializer=linear_reward_serializer,
+            serializer=lambda w: serialize_weight(
+                w,
+                ["agent", "food", "wall", "action"],
+            ),
+        )
+    elif reward_fn == RewardKind.EXPONENTIAL:
+        reward_fn_instance = ExponentialReward(
+            **common_rewardfn_args,
+            extractor=reward_extracor.extract_linear,
+            serializer=exp_reward_serializer,
         )
     elif reward_fn == RewardKind.SIGMOID:
         reward_fn_instance = SigmoidReward(
diff --git a/src/emevo/exp_utils.py b/src/emevo/exp_utils.py
index 43e99367..dd8d483c 100644
--- a/src/emevo/exp_utils.py
+++ b/src/emevo/exp_utils.py
@@ -325,16 +325,17 @@ def save_agents(
             modelpath = self.logdir.joinpath(f"trained-{uid}.eqx")
             eqx.tree_serialise_leaves(modelpath, sliced_net)
 
+    def save_profile_and_rewards(self) -> None:
+        profile_and_rewards = [
+            v.serialise() | dataclasses.asdict(self.profile_dict[k])
+            for k, v in self.reward_fn_dict.items()
+        ]
+        table = pa.Table.from_pylist(profile_and_rewards)
+        pq.write_table(table, self.logdir.joinpath("profile_and_rewards.parquet"))
+
     def finalize(self) -> None:
         if self.mode != LogMode.NONE:
-            profile_and_rewards = [
-                v.serialise() | dataclasses.asdict(self.profile_dict[k])
-                for k, v in self.reward_fn_dict.items()
-            ]
-            pq.write_table(
-                pa.Table.from_pylist(profile_and_rewards),
-                self.logdir.joinpath("profile_and_rewards.parquet"),
-            )
+            self.save_profile_and_rewards()
 
         if self.mode in [LogMode.FULL, LogMode.REWARD_AND_LOG]:
             self._save_log()
diff --git a/src/emevo/reward_fn.py b/src/emevo/reward_fn.py
index 4316ddb2..f70979da 100644
--- a/src/emevo/reward_fn.py
+++ b/src/emevo/reward_fn.py
@@ -36,6 +36,14 @@ def _item_or_np(array: jax.Array) -> float | NDArray:
         return np.array(array)
 
 
+def slice_last(w: jax.Array, i: int) -> jax.Array:
+    return jnp.squeeze(jax.lax.slice_in_dim(w, i, i + 1, axis=-1))
+
+
+def serialize_weight(w: jax.Array, keys: list[str]) -> dict[str, jax.Array]:
+    return {key: slice_last(w, i) for i, key in enumerate(keys)}
+
+
 class LinearReward(RewardFn):
     weight: jax.Array
     extractor: Callable[..., jax.Array]
@@ -63,10 +71,11 @@ def __call__(self, *args) -> jax.Array:
     def serialise(self) -> dict[str, float | NDArray]:
         return jax.tree_map(_item_or_np, self.serializer(self.weight))
 
+
 class ExponentialReward(RewardFn):
     weight: jax.Array
-    alpha: jax.Array
-    extractor: Callable[..., tuple[jax.Array, jax.Array]]
+    scale: jax.Array
+    extractor: Callable[..., jax.Array]
     serializer: Callable[[jax.Array, jax.Array], dict[str, jax.Array]]
 
     def __init__(
@@ -75,7 +84,7 @@ def __init__(
         key: chex.PRNGKey,
         n_agents: int,
         n_weights: int,
-        extractor: Callable[..., tuple[jax.Array, jax.Array]],
+        extractor: Callable[..., jax.Array],
         serializer: Callable[[jax.Array, jax.Array], dict[str, jax.Array]],
         std: float = 1.0,
         mean: float = 0.0,
@@ -88,7 +97,7 @@ def __init__(
 
     def __call__(self, *args) -> jax.Array:
         extracted = self.extractor(*args)
-        weight = (10 ** self.scale) * self.weight
+        weight = (10**self.scale) * self.weight
         return jax.vmap(jnp.dot)(extracted, weight)
 
     def serialise(self) -> dict[str, float | NDArray]: